The present invention refers to a molded part that includes a plurality of different decorative regions that adjoin each other and a method and device for the production thereof, by means of back molding several decorating films placed into a mold tool which includes a mold tool core and mold tool matrix.
The present invention refers also to a mold tool for the production of a molded part having several adjoining different decorating regions.
It is known to upgrade certain portions of mold tools for interior paneling for automotive vehicles into decorating areas with materials such as textiles, plastic films, felt or carpet materials, leather or leather imitations. The decorating areas can include, besides optical or haptic properties, also special technical functions. Normally, for the production of molded parts having integrated decorating areas, corresponding textiles or decorating films are placed into a mold tool and subsequently back molded with thermoplastic material, whereby the edges of the decorating element are usually treated in a separate work step and before the final completion of the molded part.
In order to provide a molded part with different surface structures of decorating areas, oftentimes two or more separated parts having different surface structures are produced as semi-finished goods in different mold tools and subsequently combined. This manner of production has the drawback that several production steps as well as transporting steps have to be carried out and coordinated with each other requiring a considerable amount of time and production expenditures.
In EP 1 655 122 A1, a method for the production of plastic molded parts is described where during the first production step, a first textile or decorating film is placed into a mold tool, then back molded and subsequently, a partial section is stamped out from the so produced semi-finished product. In a second step, the second textile or decorating film is then placed instead of the removed section of the semi-finished work piece and the semi-finished work piece is then finished in the area of the second textile or the second decorating film. For this method several working steps are likewise necessary in order to produce a molded part with different decorated regions.
In almost all known and practiced methods for the production of molded parts for interior paneling for motor vehicles having differently decorated areas, it is customary that either during the production of the molded part or at the latest, after the completion of the molded part, a cutting of the edges of the decorating areas has to be carried out, in order realize a fitted and optically perfect placement of the decorating element in the molded part. A neat and optically perfect execution of the marginal region of a decoration is in general a big problem in the production of such molded parts.
In laid open publication DE 10 2005 029 849 A1, a method is described for the production of a composite element for a motor vehicle, wherein at least two flat portions of an outer skin are placed next to each other in a common mold tool and provided in the mold tool across the entire surface with a common support structure. In this method it is contemplated to place portions of the outer skin as separated portions into the mold tool, whereby neighboring portions of the outer skin are sealingly overlapping at their edges. The disadvantage of this method is that the transitional regions between each of the different surfaces exhibit a rather stark optical border between the surfaces, such that this method is suitable only for the production of automotive body parts in exterior areas, where such transitions are either wanted or are hidden by means such as, for example a cover strip. For the production of molded parts with different decorating regions for the interior paneling for automotive vehicles or for door panels, this afore-described method is not suitable.
In DE 103 20 210 A1, interior paneling parts with decorating elements are described where the marginal area of the decorating element is circumferentially covered by a decorating element marginal region, whereby a flat adjoining connection between decorating element, marginal region and decorating element marginal region is realized. While that method solved the problem of the image of an uneven juncture line along the marginal area of the decorating element, without additional cutting of the decorating film, any exact line of the junctures or edges between the decorating element and the paneling can be realized only in that a multitude of different components will be glued together or combined which is very labor intensive.
There is thus the continued problem to find a method for the production of molded parts where several different decorating regions adjoining each other for the interior panel purposes of motor vehicles, with the aid of which it is possible to insert decorating regions into the molded part, that requires no additional means such as subsequent cutting or covering the marginal areas in order to realize a neat, and optically perfect transition between each of the decorating regions where the juncture line of each region is precisely delineated.